Discussions

When teams talk about code coverage, it’s often assumed that “higher is better.” While coverage is a useful metric, it doesn’t always reflect true code quality. For example, you could achieve 90% coverage by writing superficial tests that don’t validate real-world scenarios. On the other hand, a project with 70% coverage but strong assertion-based tests could actually be more reliable.

A few key points to keep in mind:

Coverage ≠ Quality – Code coverage only measures what parts of your code are executed by tests, not how well those tests validate logic.

Focus on Critical Paths – Instead of chasing 100%, prioritize coverage for high-risk areas like authentication, payments, or APIs.

Branch Coverage Matters – Testing different decision paths is more valuable than just covering lines.

Complement with Other Metrics – Pair coverage with mutation testing, code reviews, and static analysis to get a fuller picture of quality.

In practice, code coverage should be seen as a guiding metric, not the ultimate goal. It highlights blind spots, but real confidence comes from meaningful tests that simulate actual usage and edge cases.